Abrasive belt surfacing apparatus



April 7, 1959 J`. R. MaclN-rosH 2,880,594

ABRAsIvE BELT SURFACING APPARATUS Filed Feb. 1e, 1955 IN VEN TOR."

A TTRNE YS United States Patent O ABRASIVE BELT SURFACING APPARATUS John Roderick MacIntosh, Chicago, Ill.

Application February 18, 1955, Serial No. 489,008

9 Claims. (Cl. 118-11) entrained about suitable pulley wheels with the abrasive coated surface out, are used in abrading operations, for example, in the polishing of castings. Heretofore, the belts have been discarded after being used until the abrasive coating is worn because no way has been known to effectively and commercially resurface such worn belts. It is, accordingly, an object of this invention to provide apparatus forv applying an abrasive surface toabrasive belts andlthat is especially adapted for the resurfacing. or reconditioning. of worn abrasive belts. `Another object of the invention is the provision of apparatus that functions automatically to apply adhesive to a belt, apply abrasive particles to the adhesive coated surface of the belt, and thereafter dry the adhesive all in a timed se-` quential cycle. v Still another object is in providing resurfacing apparatus for reconditioning endless abrasive belts inwhich the belts are entrained about pulley wheels and are moved through a plurality of stations; one wherein adhesive is sprayed under pressure onto the surface of the belt; another where abrasive particles are sprayed under pressure -onto the adhesive coating of the belt; and still another wherein the adhesive having the abrasive particles embedded therein is dried as the belt advances along its path of movement. A further object is in the provision of apparatus as described, in which means are provided for accurately controlling the pressure employed in spraying the adhesive onto a belt, and also the pressure employed in spraying the abrasive particles onto the belt, the spray nozzles being oriented so thatthe adhesive is applied uniformly over the belt and the abrasive materials are embedded into the adhesive coating and uniformly over the surface. Additional objects and advantages will appear as the specification proceeds.

, An embodiment of the invention is illustrated in the accompanying drawing, in which Figure l is a'front view in elevation of the apparatus; Fig. 2 is a side view in elevation of the apparatus; and Fig. 3 is a broken enlarged sectional View taken on the line 3-3 of Fig. 1.

The over-all apparatus as shown in Figs. l and Z is designated generally with the letter A, and is seen to comprise a frame 10 formed of a plurality of channel members interconnected together. The channel members include front or forward channel members 11 and 12 that are inclined upwardly and rearwardly and that are connected to generally vertical rear channel members 14 and 15 by a plurality of transverse struts 16 and 17 that are positioned adjacent the top of the front and rear channel members. Additional transverse struts 18 and 119are provided intermediate thevends of the front and ICE rear channel members and longitudinally extending struts 20 and 21 adjacent the top of the front and rear channel members, and 22 and 23 intermediate the ends of the channel members may be provided to reinforce the structure.

Carried by the spaced-apart longitudinally extending beams or struts 21 is a motor 24 equipped with a gear reducer and pulley wheel 25 driven thereby, and ythat is entrained by a belt 26 operatively connected with a drive pulley 27 supported for rotation in pillow bearing 28 secured to an angle support 29. A similar angle support 30 is provided adjacent the opposite side of the structure and carries a pillow block or bearing 31 that provides a rotatable mounting for an idler pulley 32. As is seen best in Figs. l and 2, the longitudinally extending beams 22 and 23 have rigidly aixed thereto a depending carrier 33 having an axially extending slot 34 therein, and having also an aperture or opening extending therethrough intermediate the ends thereof that receives a pin 35 therein. The carrier is adapted to provide a support for a take-up pulley wheel 36 that is mounted for rotatable movement about an axle 37 and the axle 37 is supported within the slot or channel 34 for movement longitudinally therealong. An abrasive belt 38 is adapted to be entrained about the pulley wheels 27, 32 and 36, as is shown in Fig. l. To place the belt 38 over the pulley wheels, or to remove the same therefrom, the take-up pulley 36 may be moved upwardly within the channel 34 and supported in its uppermost position by the pin 35. In use the take-up pulley 36 is permitted to move downwardly freely within the channel 34 and to thereby tension the belt 38 in its path of travel about the pulley wheels.

Carried by the frame 10, and preferably through an L-shaped angle member 39 affixed thereto, is a cement tank 40 that at its upper end has a removable cover 41 and at its lower end is provided with a restricted discharge outlet 42. A flexible ilow conduit 43 provides communication between the outlet 42 and a spray gun or spray nozzle 44 that is supported for pivotal movement in a generally horizontal plane by an arm 45 swingably carried by a post 46 that in turn is affixed to the frame 10.

On the opposite side of the frame 10 an abrasive hopper 47 having a swingable cover 48 is secured to the frame 10 through an L-shaped channel member 49. At its lower end, the hopper 47 is provided with a discharge outlet 50 that is restricted and that communicates through a conduit 51 with a spray gun or nozzle 52. The nozzle 52 is adapted to be swung in a generally horizontal plane and is supported by an arm and standard similar to the arm 45 and standard 46, heretofore described in conjunction with the spray nozzle 44.

Fluid under pressure is fed to the nozzles 44 and 52, and also to the cement tank 40, so as to provide for the spraying of adhesive and abrasive materials onto the -belt 38. Such fluidunder pressure, which may be air for example, is supplied through an inlet conduit 53 and pressure regulator valve 54, which may be equipped with a pressure indicator 55, connected to a manifold or distribution conduit 56. The control valve 54, as is seen in Fig. l, is adapted to be manually adjusted to provide a uniform and constant pressure to the distribution conduit 56. Pressure regulator valves 56a and 56b are included in the respective branches of conduit 56 leading from the valve 54 and permit different pressures to be provided in the branches. A solenoid controlled valve 57 is interposed in the conduit branch 57a beyond the valve 56b and controls the llow of pressure fluid therethrough to the fitting 58 that distributes the fluid to a throttling valve 59 adapted to be manually adjusted and which may be provided with a pressure indicating dial 60, as is shown in Fig. 2, and which feeds pressure fluid directly into the tank 4i) through a conduit 61. A conduit 57b communicates with conduit 56 at a point between the valves 57 and 56]: and carries pressure fluid to a throttling valve 62 which is adapted to be manually regulated and that may be provided with a pressure indicating dial 63, as is seen in Fig. 2, which in turn feeds directly into the spray nozzle 44 through a conduit 64 that is flexible.

A solenoid controlled valve 65 is also interposed in the distribution conduit 56 for controlling the liow of pressure fluid to a pressure regulator vulve 66 that is adapted to be manually adjusted and is preferably provided with a pressure indicating dial and that in turn feeds directly into the spray nozzle 52 through a flexible conduit 67.

As is seen best in Fig. l, the motor 24 is connected through a conduit 63 with a distribution box 69 and similarly the solenoid 57 and the solenoid 65 are connected respectively through conduits 70 and 7l with the distribution box 69. Electric power is fed to the distribution box 69 through a cable 72 that is adapted to be connected to a suitable power outlet, not shown. The distribution box 69 is also connected through a cable 73, having an ori-off push `button type switch 74 interposed therein with a control box or cabinet 75 that provides a housing and mounting for a plurality of timers and automatic sequence controls that function to control operation of the motor 24, actuation of the solenoids 57 and 65, and actuation of a heater assembly 76 that will be subsequently described, whenever the push button switch 74 is energized.

The heating element 76 may take various forms and preferably includes an elongated generally transversely parabolic reflector 77 that is equipped adjacent opposite ends thereof with a socket 78 having a heating element, such as an infrared tube 79 extending therebetween. Secured to the bottom of the reflector 77 and extending longitudinally thereof is a wiring and mounting channel 88 that is secured at opposite ends thereof to a pair of supports 81 and 82 that are carried by spaced-apart depending support members 83 and 84. The members 83 and 84 are rigidly secured to the longitudinally extending strut 21, as is seen ibest in Fig. 3. The wiring for the heater 76 will be connected through the distribution box 69 with the control box 75 so that it will be energized in timed relation with the motor and solenoids 57 and 65 whenever the push button switch 74 is actuated.

Preferably the motor 24 and distribution box 69 are isolated from the heater 76, and this may be accomplished by mounting a stainless steel reflector 85 that is secured to the longitudinal struts 20 and 21 in any suitable manner, such as by welding, and that is positioned between the heater and the elements or members it is to isolate. It is apparent from Fig. 3 that the reflector 77 opens upwardly and therefore directs heat toward the endless abrasive ibelt 38 as it passes over the pulley wheel 32 and between the pulley wheels 27 and 32. The members 8l and 82 may be secured respectively to the supports 83 and 84 by bolts 86, as is shown best in Figure 3. If desired, the pulley wheel 32 may be equipped with a shaft 87 that is elongated and that in in addition to extending through the pillow bearing 31, may also extend through a pillow bearing 88 that is carried by an angular support 89 and project outwardly therefrom.

Operation In use of the apparatus the conduit 53 is connected to a suitable source of fluid under pressure and the valve 54 is adjusted so as to provide the desired fluid pressure in the distribution conduit 56. The conduit 72 is connected to a suitable power source and the tank 40 is illed with a liquid adhesive; the hopper 47 is filled with abrasive particles. Next, an abrasive belt 38, either new and which has not as yet been coated with an abrasive,

4 or one that is used and requires reconditioning, is entrained about the pulley wheels 27, 32 and 36. This is readily accomplished by moving the take-up wheel 36 upwardly along the carrier 33 and supporting it in the uppermost position by the removable pin 35. When the belt is in place, the pin 35 is withdrawn and the take-up wheel 36 is permitted to move downwardly so as to engage and tension the belt 38.

When it is desired to institute a cycle of operation, the push button switch 74 is depressed to actuate the timer controls within the control box 75. The motor 24 is first energized and it rotates the drive pully 27 which then starts the belt 38 in motion along its path of movement. At substantially the same time, the solenoid control valve 57 is energized so as to open the distribution conduit 56 and thereby supply pressure uid to the tank 48 and spray nozzle 44. Preferably, the control valves 59 and 62 are first adjusted so that the required pressures are delivered to the tank 40 and nozzle 44. The specific pressures employed will depend upon the distance separating the spray nozzle 44 and belt 38 and also upon the character of the liquid adhesive being employed. When the solenoid controlled valve 57 is energized, liquid adhesive will spray from the nozzle 44 and onto the outer surface of the `belt 38, as is shown in Fig. l.

Shortly thereafter, and about the time that the surface of the belt 38, having the adhesive coating thereon, advances into a position adjacent the nozzle 52, the solenoid controlled valve 65 is energized to open the flow conduit 56 and to deliver pressure fluid through the valve 66 to the nozzle 52. Preferably the valve 66 is first adjusted so as to deliver the desired pressure to the nozzle 52. Abrasive particles will then be sprayed from the nozzle and onto the belt 38 as it advances in front of the nozzle.

The heater 76 is also energized and as the portions of the belt that are coated with adhesive and with abrasive materials are moved over the pulley Wheel 32 and over the heater 76, heat will be directed upwardly against the under surface of the belt and will be effective to harden the adhesive and thereby rigidly and firmly anchor the abrasive particles to the outer surface of the belt. After the entire surface of the belt has been coated with the adhesive, the timer controls are effective to de-energize the solenoid valve 57 and to terminate spraying of the adhesive onto the belt. Similarly, and shortly thereafter, the timer controls Will de-energze the solenoid valve 65 to terminate the spraying of abrasives from the nozzle 52 and onto the surface of the belt 38. Finally, the timer controls will de-encrgize the motor 24 and deactuate the heater 76 and the surfacing or coating cycle will then be complete. The coated and dried belt is then removed from the pulley Wheels by simply moving the take-up pulley 36 upwardly and anchoring it in position by the pin 35, and thereafter pulling the belt from the wheels 27 and 32. Another belt can then be positioned in the apparatus.

It is noted, particularly in Fig. 1, that the nozzle 44 is angled downwardly slightly by a few degrees, and the downward inclination is along the path of travel of the belt 38 and in the direction of that travel. This positioning of the nozzle is effective to apply a coat of adhesive upon the outer surface of the belt 38 that is evenly and uniformly distributed thereover. On the other hand, the nozzle 52 is angled downwardly and toward the belt 38 and is directed oppositely to the path of movement of the belt 38. Such positioning of the nozzle 52 is effective to cause an embedding of the abrasive materials into the adhesive coating and to insure a secure anchoring of the abrasive particles to the belt. It is found that the adhesive particles are deposited in myriad fashion upon the surface of the belt, but are uniformly distributed thereover. At the same time, the embedding of the particles into the adhesive causes an eectve anchoring of the adhesive to the abrasive particles and the belt, after the surfacing thereof, can be used for long periods. It has been found, for example, that where an abrasive belt is purchased new and is then used in an industrial application that in one specic case one hundred thirty-six separate pieces of equipment were abraded or polished with the belt before it became worn and had to be discarded. This same belt was then mounted in the apparatus shown and described, and the surface thereof was recoated with abrasive materials. The belt was then taken and employed in the same industrial application, and was found to polish or abrade one hundred seventy-eight pieces of equipment before it again required resurfacing. Thus, the resurfacing was found in that case, and in numerous other test cases, to provide an abrasive belt with at least as good and generally better qualities than the abrasive belt had when purchased new. The cost of resurfacing the belt is small compared to the new purchase price thereof, and it will be appreciated that considerable savings can be realized in any industry wherein a considerable number of abrasive belts are used in any given period.

Conceivably, the sequential and timed operation of the units, as theretofore described, could be replaced with means for manually actuating the elements. The belt moves relatively slowly through the apparatus, and I have found that preferably a speed of about one complete revolution in about twenty-nine seconds provides suicient time for the application of the liquid adhesive, the depositing of abrasive particles thereon, and the drying of the adhesive.

In operation of a specific machine, an entire belt having a length of about 168 inches is coated with adhesive in about twenty-live seconds. About twelve seconds after the application of adhesive starts, abrasive is discharged onto the belt and in about live seconds thereafter the heater is energized. Preferably the belt was passed through the heater twice before the heating cycle was terminated. In use, the distance between the nozzles and a belt will be increased as the belt width increases and vice versa. The air pressures employed will be varied with different types of adhesives and different types of abrasives, that is, a heavier abrasive grain will ordinarily require a greater air pressure. The angular orientation of the adhesive nozzle provides uniformity of application of the adhesive and prevents any tendency of the adhesive to stratify or build up in certain areas. The angle of the abrasive nozzle keeps the abrasive from striking the covered surface of the belt and causes the abrasive grains to imbed themselves in the adhesive.

p While in the foregoing specification an embodiment of the invention has been illustrated and described in considerable detail for purposes of adequately and thoroughly presenting the invention, it will be apparent to those skilled in the art that numerous changes may be made in these details without departing from the spirit and principles of the invention.

I claim: y

l. In apparatus for surfacing an endless abrasive belt, a frame, a plurality of pulley wheels rotatably supported in said frame, one of said wheels being driven, and being adapted to have an endless belt entrained thereabout, a hopper carried by said frame adjacent one side thereof and being adapted to receive abrasive materials therein, a tank carried by said frame adjacent the other side thereof and being adapted to receive liquid adhesive therein, a spray nuozzle connected to said hopper for receiving abrasives therefrom and being arranged for spraying abrasives onto an endless belt moving thereby, a second spray nozzle connected to said tank and being rarranged for spraying adhesives onto a belt moving l thereby, a fluid pressure distribution conduit adapted to communicate with a source of iluid under pressure and being connected through a pressure regulator valve with said first mentioned spray nozzle, said distribution conduit also being connected through a pressure regulator valve with said tank and through a pressure regulator valve with said second mentioned spray nozzle, solenoid controlled valves in said distribution conduit and being operative respectively to control the flow of pressure uid to said first mentioned spray nozzle and to said tank and second mentioned spray nozzle, means for controlling said solenoid controlled valves to selectively establish and interrupt the ilow of pressure uid therethrough, and a heater oriented with respect to a belt passing thereby for heating the belt to dry the adhesive coating thereon after the adhesive has been embedded with abrasive materials. i

2. The structure of claim l in which one of said pulley wheels is a take-up wheel and is selectively movable to a release position to yfacilitate the entrainment and removal of an endless belt about said pulley wheels.

3. The structure of claim 1 in which said heater is elongated and is directed toward the side of an endless belt opposite the one coated with adhesive and abrasive materials.

4. The structure of claim 1- in which said first mentioned spray nozzle is directed toward and in opposition to the path of movement of an endless belt thereby, in which said second mentioned spray nozzle is directed toward and along the path of movement of a belt advancing thereby, and in whicheach of vsaid spray nozzles is supported vfor movement along a path generally transverse to the path ofmovement of 'an endleess belt advancing thereby.`4A

5. The apparatus of claim l in which timer control elements are provided for sequentially operating said solenoid control valves to sequentially apply an adhesive coating to a belt and to thereafter embed adhesive materials into the adhesive coating of the belt.

6. In apparatus for surfacing endless abrasive belts and the like, a frame, a plurality of pulley wheels rotatably supported in said frame and adapted to have an abrasive belt entrained thereabout, means for rotating one of said wheels so as to move such belt through a predetermined path, a first spray nozzle arranged for spraying abrasives onto an abrasive belt moving thereby, a second spray nozzle arranged for spraying adhesives onto such an abrasive belt moving thereby, a fluid pressure distribution conduit adapted to communicate with a source of uid under presssure and being connected with said first spray nozzle and also with said second spray nozzle, valve means in said distribution conduit and being operative to control the ow of pressure lluid to said spray nozzles, means for operatively controlling said valve means to selectively establish and interrupt the flow of pressure fluid therethrough, means for supplying abrasives to said first spray nozzle, means for supplying adhesive to said second spray nozzle, and a heater oriented with respect to such a belt for drying the adhesive coating thereon after the adhesive has had abrasive materials embedded therein.

7. In apparatus for resurfacing endless abrasive belts, a frame, a plurality of pulley wheels rotatably supported in said frame and adapted to have an abrasive belt entrained thereabout, one of said pulley wheels being adjustably carried by said frame so as to afford selection of the length of the path of travel through which such an entrained belt is moved to enable said apparatus to accommodate belts of different lengths, drive means for rotating one of said wheels, a heater carried by said frame and being disposed between certain of said wheels for passing an abrasive belt therethrough, an adhesive spray nozzle carried by said frame and being positioned intermediate a pair of said pulley wheels and oriented so as to direct adhesive onto the surface of an abrasive belt entrained about said wheels, adhesive supply means connected with said nozzle for supplying adhesive thereto. an abrasive spray nozzle carried by said frame intermediate a pair of said wheels and being oriented so aS to direct abrasive particles onto the surface of an abrasive belt entrained about said wheels, abrasive supply means connected with said abrasive nozzle for supplying abrasives thereto, a distribution conduit adapted to be connected to a source of fluid under pressure and being connected to said respective spray nozzles, control valve means interposed in said distribution conduit for regulating the supply of uid under pressure to said adhesive spray nozzle, control valve means interposed in said distribution conduit for regulating the supply of uid under pressure to said abrasive spray nozzle, and means for operatively controlling each of said valve means.

8. In apparatus of the character described, support means for carrying and advancing a belt through a plurality of operating stations, an adhesive spray nozzle positioned along the path of movement of such belt and oriented for spraying an adhesive onto a surface thereof, means for supplying adhesive to said spray nozzle, an abrasive spray nozzle located along the path of movement of such belt and oriented with respect thereto for spraying abrasive particles onto the adhesive coating thereon, means for supplying such particles to said abrasive spray nozzle, regulator means for said adhesive spray nozzle, regulator means for said abrasive spray nozzle, and control means for operating each of said regulator means to govern the emission of materials from the respective nozzles, said control means defining an operational cycle wherein said adhesive spray nozzle is actuated to deposit a coating on a belt advanced therepast, wherein said abrasive spray nozzle is then actuated when the adhesive coated portion of such belt is advanced therepast to deposit abrasive particles thereonto, and wherein the adhesive spray nozzle and the abrasive spray nozzle are respectively deactuated when the entire surface of such belt has been coated with adhesive and coated with abrasive particles.

9. The structure of claim 8 in which a heater is provided for drying the abrasive-covered adhesive coating on such belt, in which regulator means are provided for governing said heater, and in which said control means operate said last mentioned regulator means to actuate said heater when the abrasive-covered adhesive coating of such belt is advanced therepast and deactuates the heater after such composite coating has been dried.

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